Greenland on Verge of Meltdown

Deniers Jump on NASA Gaff, While Greenland on Verge of MeltdownBy Stephen LeahyAug 16, 2007 (IPS) – Scientists warn that climate change tipping points are imminent, and will lead to potentially catastrophic events like a seven-metre sea level rise. Meanwhile, conservatives in the North American media are focusing on a NASA admission of a climate calculation error.

First the error.

U.S. and Canadian mainstream media and Internet news sites devoted tens of thousands of words over the past week to NASA’s Goddard Institute for Space Studies admission that it made a calculation error ranking 1998 as the warmest year on record in the United States when it should have been 1934.

While the difference is only a few hundredths of a degree, the climate change deniers variously cite this as evidence of NASA (U.S. National Aeronautics and Space Administration) incompetence and cover-up, and more proof that global warming is a hoax.

The neo-conservative U.S. network Fox News reported Aug. 9 that “the discovery of an embarrassing temperature error rained on their (the ‘alarmists’) parade.” Canada’s National Post on Monday said the reasons given for climate change “hysteria” were “no longer true”.

The Washington Post and the Toronto Star both noted the reaction of conservatives in the media and in the blogosphere, including outspoken radio talk-show host Rush Limbaugh, who said: “We have proof of man-made global warming. The man-made global warming is inside NASA. The man-made global warming is in the scientific community with false data.”

Forgotten in all this is that U.S. temperatures are only a small part of the global mean average temperatures, which remain unchanged even with NASA’s re-calculation. Nine of the 10 hottest years globally have occurred in the last decade, although that is not the case in the United States, where there were several very warm years in the 1930s.

Now the warning: The complete collapse of the massive Greenland Ice Sheet — which has a mean height of about two kilometres — now appears inevitable, and could raise sea levels seven metres.

“It’s a sobering message, I think,” says Tim Lenton, of the School of Environmental Sciences at Britain’s University of East Anglia.

Lenton’s research group surveyed climate and glacial experts around the world and the consensus is that the recent evidence shows that rising temperatures will soon reach the Greenland Ice Sheet’s “tipping point”, where it will break up within 300 years, raising sea levels by seven metres and flooding millions out their homes long before the year 2300.

Recent calculations show the Greenland collapse could be triggered by temperature rise of just 1 degree Celsius warmer than today. This is an example of what scientists call a “non-linear response”, in which a small change can make a big difference, more commonly described as “tipping points”.

And this point is coming much sooner than it looks. Due to a time lag in the atmospheric warming response, even if there were no more greenhouse gas emissions from this day forward, temperatures would still rise another 0.6 degrees Celsius.

“I don’t want to say the Greenland meltdown is inevitable, but it will be very difficult to avoid,” Lenton told IPS.

James Hansen, head of NASA’s Goddard Institute for Space Studies, believes that without drastic international efforts, a sea level rise of up to five metres is possible.

“In my opinion, if the world warms by 2 to 3 degrees Celsius, such massive sea level rise is inevitable, and a substantial fraction of the rise would occur within a century,” Hansen wrote in the Jul. 25 issue of New Scientist magazine.

He notes that the last time the Earth was that much warmer was around three million years ago: “It was a dramatically different planet then, with no Arctic sea ice in the warm seasons and sea level about 25 metres higher, give or take 10 metres.”

[…] by Stephen on September 7th, 2007 Chilling from-the-scene update on my Greenland on Verge of Meltdown article in August: the Greenland ice cap is melting so quickly that it is triggering earthquakes as […]